The present invention relates generally to fluid infusion methods for performing peritoneal dialysis on a patient, especially continuous ambulatory peritoneal dialysis (CAPD). The present invention further relates to methods and apparatus for preventing peritonitis in a patient undergoing peritoneal dialysis treatment.
In the treatment of patients suffering acute or a chronic renal insufficiency due to loss of normal kidney function, dialysis therapy is employed. The two general categories of dialysis therapy are hemodialysis and peritoneal dialysis. In hemodialysis, a patient's blood is cleansed by passage through an artificial kidney. In peritoneal dialysis, dialysis fluid is infused into the patient's peritoneal cavity, which is lined by the peritoneal membrane, and metabolites are removed from the patient's blood by diffusion across the peritoneal membrane; water is also removed because of the osmotic effect of the dialysis fluid.
Within the general category of peritoneal dialysis, modern application has resulted in several peritoneal dialysis techniques. Foremost among the peritoneal dialysis techniques are standard intermittent peritoneal dialysis (IPD) and continuous ambulatory peritoneal dialysis (CAPD).
The usual clinical procedure for a patient beginning peritoneal dialysis, after the surgical implantation of a catheter into the peritoneal cavity, involves infusion of dialysis fluid into the peritoneal cavity of a patient, where it is allowed to equilibrate for a period of time and then drain from the peritoneal cavity.
IPD is performed intermittently, with intensive treatments being conducted two to four times per week. In each treatment, dialysis fluid is rapidly infused and allowed to equilibrate for up to 90 minutes, after which it is removed.
IPD is performed using clamps, connection tubing, and exchange containers, the manipulation of which entails careful and time-consuming attention by a competent nursing staff. The frequent handling of fresh and waste dialysis fluid bottles and the connection apparatus presents a substantial risk of infection to the peritoneum. Because of the high risk of infection, and because trained personnel need to be available to perform IPD, IPD has not gained widespread usage. In an attempt to reduce the risk of infection and minimize nursing time, automatic dialysis fluid cycling equipment for automating the dialysis procedure has been adopted in many instances.
Continuous ambulatory peritoneal dialysis (CAPD), which is a recent medical discovery, differs from IPD. In CAPD, multiple dialysis fluid exchanges are performed daily with a significantly longer interval between exchanges being employed when compared with IPD, such that a substantially constant presence of dialysis fluid is maintained within a patient at all times. A description of the continuous ambulatory peritoneal dialysis technique may be found in Popovich, et al. U.S. Pat. No. 4,239,041, issued Dec. 16, 1980 and entitled "METHOD FOR CONTINUOUS AMBULATORY PERITONEAL DIALYSIS."
To perform CAPD, an in-dwelling catheter capable of having a peritoneum access tube connected thereto is implanted in the peritoneal cavity. A dialysis solution bag containing about two liters of dialysis solution is attached to the free end of the tube, and the fluid is infused into the peritoneal cavity. The dialysis solution bag is preferably plastic and flexible. Dianeal.RTM. dialysis solution in plastic, flexible bags is manufactured and sold by Travenol Laboratories, Inc., Deerfield, Ill. and may be used in practicing CAPD.
After infusion, the access tube is clamped off and the patient folds up the empty bag, which is then carried by the patient while dialysis takes place. Alternatively, the empty bag can be disconnected from the access tube and a cap placed on the external coupling connector at the end of the access tube; when the patient thus "caps off", the patient may use glass or plastic bottles of dialysis solution as an alternative to the preferred plastic bags since a primary benefit of the plastic bags is that they can be rolled for carrying by the patient while dialysis takes place.
After the period of dialysis fluid residence (dwell), the patient, if wearing the bag, unwraps the empty plastic bag, lowers it to the floor, releases the clamp and lets the waste-laden dialysis fluid drain out of the peritoneal cavity. Next a new bag of fluid is attached, and fresh fluid is infused into the peritoneal cavity. If the patient is not wearing the empty bag during dwell, the cap on the end of the supply tube is removed and a drainage bag or other suitable container is attached thereto. After draining of fluid from the peritoneal cavity, a new bag of fresh fluid is attached and the fresh fluid is infused.
Continuous ambulatory peritoneal dialysis permits a patient to carry out his normal daily activities while dialysis is taking place. Also, because CAPD is much simpler than IPD, a patient can readily administer the treatment himself at home.
For many years, peritonitis has been a complication of long-term peritoneal dialysis for end-stage kidney disease. With CAPD, the risk of peritonitis is reduced, but improved infusion methods and apparatus are needed to permit CAPD to reach its full potential. The present invention seeks to reduce the incidence of infection in peritoneal dialysis procedures in general and in continuous ambulatory peritoneal dialysis in particular.